Applications of swivel couplings for air tube and hose line connections in industrial and commercial environments require resistance to harsh environmental conditions and reliability under stress during installation and operation. For example, in applications in the freight hauling trucking and transportation industry, tractor-trailer air brake fittings and hose including swivel couplings for tube assemblies undergo continuous exposure to the elements, often in frigid conditions. Winter road salts and brine, dirt, grease, and other solvents erode fittings and assemblies of critical air brake tube and hose connections, putting the safety of the driver and highway motorists at risk.
Tube and hose lines, as well as grips and couplings for such tube and hose lines used within harsh industrial and commercial environments generally must withstand such harsh environments as well as perform reliably under the stress and strain forces encountered during installation and operation. Such tube and hose lines may involve high pressure hydraulics or air and often require some flexibility of the tube or hose.
Hoses and tubes are commonly used in applications within the freight hauling industry, for example, to supply pressurized air for air brake operation between a tractor cab unit and a freight trailer, or from a locomotive to railway air brakes on railroad cars. Inherent to the freight industry is the constant coupling and decoupling of hoses/tubes as trailers are left for loading or unloading and other trailers are picked up for delivery. Various types of components including swivel couplings, are used to interconnect hose/tube sections to other hoses/tubes sections and to terminals.
In such harsh operating environments, hose assemblies are susceptible to breaking and must be capable of being quickly and properly repaired in order to ensure safe operation of the vehicle while minimizing out of service time. Some hose repair kits utilize live swivel couplings which may be interconnected to a failed hose end. Typical hose end repair kits require multiple wrenches to be used to affix the swivel coupling to the hose end which makes repair more complicated and time consuming. Also, certain kits require crimping of the components of the live swivel together to interconnect the components. This requires the use of materials such as steel rather than the more malleable brass to prevent over-torquing and leakage. This leads to corrosion issues and fitting seize-up. It also makes field installation more difficult and less precise given the variability in the amount of crimping pressures likely to be applied by various users making repairs.